With heightened security requirements at facilities across the country and overseas, the need has become apparent for a device that can easily upgrade gates and fences to meet necessary crash barrier requirements. A simple device in use at Argonne National Laboratory since the mid-1980s provides an approach that has been improved with this invention. That device is believed to be the “novel gate barrier” determined to be in the public domain according to a letter on Argonne National Laboratory letterhead from E. Gale Pewitt, Chief Operations Officer, to Mr. David Fitzgerald at the Tennessee Innovation Center, dated Sep. 22, 1987. The “novel gate barrier” is simply a straight steel pipe with a wire rope cable through it. The cable ends are connected so that the cable forms a loop, part inside and part outside the pipe. The pipe is attached to the fence and the cable loop hangs below the pipe. A variation at another gate apparently has metal standoffs welded to the pipe and clamped to the cable to hold the cable above the pipe. The pipe is attached to the gate, and two bollards with hooks will catch the cable loop when impacted in such a way that the pipe passes through the bollards. Barrier Concepts, Inc., Crisp & Associates, and Performance Development Corporation have offered this “novel gate barrier” style barrier reinforcement for sale since the late 1980s.
The various versions of this “novel gate barrier” reinforcing system permit the full force of impact to bear as a concentrated load on one thickness of cable at the bollard catch-hook after the pipe has pushed through. Similarly, these systems do not provide protection against cutting action of the pipe ends or the standoffs on the wire rope.
In early 2003, Performance Development Corporation offered a system wherein two straight sections of pipe reinforced with cable and connected to each other were to be attached to a gate. This system was heavier and more complex in that it required additional cable fittings, additional pipe, an additional row of catch hooks on the bollards, and more precise placement of the attachments to the gate.
Although it is not known whether the “novel gate barrier” version used an I-beam to reinforce the bollards, the Barrier Concepts, Inc. and Performance Development Corporation versions did. Installation of reinforcing steel in the bollards can be inconsistent, potentially reducing the benefit of the reinforcement in resisting higher impact crashes.
The “novel gate barrier,” the Barrier Concepts, Inc., and the early 2003 Performance Development Corporation bollards all used catch hooks fabricated from pipe, welded to the surface of the bollard.
Our improved Security Barrier Reinforcing System 1) provides for distribution of the loading on the cable at impact, 2) transfers critical impact loading from the cable to the pipe, 3) eliminates sharp edges that could cut the cable from long term use or impact, 4) uses an improved catch hook design that is welded both at the surface and at the opposite side of the bollard, and 5) includes a modified reinforcement technique for the bollard to facilitate installation.
While numerous gates and barriers have been developed to stop or ensnare vehicles, patented devices to modify or strengthen existing gates and barriers are uncommon. Fischer's Fortified Gate System addressed in U.S. Pat. No. 5,740,629 (issued Apr. 21, 1998) and U.S. Pat. No. 5,987,816 (issued Nov. 23, 1999) is an example of such a reinforced system. The Fischer system, however, requires anchors with a spring-loaded locking mechanism, and does not provide a passive mechanism such as trapping the bollard catch to arrest forward motion. Once installed, our Security Barrier Reinforcing System does not require operation of any active elements to perform its function.
Field of Search:                Classifications 49/9; 256/13.1; 256/73        